Most trailers that are towed by vehicles may be connected to the towing vehicle's electrical system. The towing vehicle's electrical system may operate the trailer's lights and brakes, and may even supply power for electrical appliances on the trailer (e.g., interior lights, refrigerators, and winches). To facilitate the electrical connection, the trailer is usually equipped with a standard “pigtail” electrical connector that couples to a corresponding electrical connector on the towing vehicle. The electrical connector on the towing vehicle may be either original equipment installed by the manufacturer, or an after-market device installed by the consumer.
There are several variations in the types of connector technologies that are used to couple a trailer to the electrical system of its towing vehicle. These include “4-way round” and “4-way flat” connector technologies, “5-way round” and “5-way flat” connector technologies, “6-way round” and “6-way square” connector technologies, and “7-way round, round-pin” and “7-way round, flat-pin” connector technologies. Except for the “7-way round, flat-pin” connector technology, these various technologies utilize a combination of round male electrical pins and cylindrical female electrical terminals to form the various individual electrical connections. FIGS. 1A and 1B, for example, show perspective views of a trailer connector 100 and a towing vehicle connector 110, respectively, in accordance with the “4-way round” connector technology. As can be seen in the figures, the trailer connector comprises a male plug 120 having four cylindrical female electrical terminals 130. The towing vehicle connector, on the other hand, comprises a female socket 140 having four inversely arranged round male electrical pins 150. Each of these four round male electrical pins in the towing vehicle's female socket is inserted into and makes electrical contact with a corresponding cylindrical female electrical terminal in the trailer's male plug when the male plug is correctly inserted into the female socket.
Because of their relationship to safety, it is critical that each electrical contact on the trailer's connector, whether it is a round male electrical pin or a cylindrical female electrical terminal, be capable of forming a low-resistance electrical connection with its corresponding electrical contact on the towing vehicle's connector. Unfortunately, this requirement is made more difficult by the environment in which these connectors operate. Because of their placement in relation to the towing vehicle, these connectors and their electrical contacts are frequently exposed to dirt and moisture. Dirt can coat the electrical contacts, forming a high-resistance surface layer. Moisture, especially when combined with road salt, can corrode the electrical contacts. In an attempt to mitigate these issues, some connectors include covers for protecting their electrical contacts when the connectors are not in use. The towing vehicle connector 110 in FIG. 1B, for example, includes a spring-loaded hatch cover 160. Nevertheless, such covers are often ineffective because of the extreme conditions to which these connectors are exposed. This is true especially for corrosion.
For the foregoing reasons, there is a need for a low-cost apparatus that makes it easy and convenient to clean dirt and corrosion from cylindrical female electrical terminals on trailer connectors as well as other types of connectors so that these electrical terminals are capable of reliably forming low-resistance electrical connections.